An Analysis of Arguments Advanced via Twitter in an Advocacy Campaign to Promote Electronic Nicotine Delivery Systems

Abstract Introduction Advocates of electronic nicotine delivery systems (ENDS) increasingly use Twitter to promote liberal ENDS policies. “World Vape Day” (WVD) is an annual campaign organized by pro-ENDS advocacy groups, some of which have links to the nicotine industry (eg, via funding from the “Foundation for a Smoke-Free World”). In 2020, the campaign used dedicated social media accounts to disseminate WVD-branded images and campaign messages. We examined tweets posted as part of WVD 2020 to identify and analyze pro-ENDS policy arguments. Aims and Methods We extracted tweets posted between 26 May and 3 June 2020 that included the hashtag #WorldVapeDay. We used qualitative thematic analysis to code a random sample (n = 2200) of approximately half the original English language tweets (n = 4387) and used descriptive analysis to identify the most frequently used co-hashtags. Results Arguments related to four themes: harm reduction, smoking cessation, rights and justice, and opposition to ENDS restrictions. Tweets criticized individuals and groups perceived as opposing liberal ENDS regulation, and used personal testimonials to frame ENDS as a harm reduction tool and life-saving smoking cessation aid. Tweets also advanced rights-based arguments, such as privileging adults’ rights over children’s rights, and calling for greater recognition of consumers’ voices. Tweets frequently used hashtags associated with the WHO and World No Tobacco Day (WNTD). Conclusions The WVD campaign presented a series of linked pro-ENDS arguments seemingly aimed at policy-makers, and strategically integrated with the WHO’s WNTD campaign. Critically assessing pro-ENDS arguments and the campaigns used to promote these is vital to helping policy actors develop proportionate ENDS policy. Implications Social media platforms have considerable potential to influence policy actors. Tweets are easily generated and duplicated, creating an impression of sizeable and influential stakeholders. Evidence that the “World Vape Day” campaign was supported by groups with industry links, and targeted—at least in part—at WHO officials and those who follow the WHO World No Tobacco Day campaign, highlights the importance of critically reviewing such campaigns. Further research could examine how health advocates could engage in pro-ENDS campaigns to support balanced messaging and informed policy-making.


Introduction
Several studies conclude that electronic nicotine delivery systems (ENDS) are less harmful than smoking 1, 2 ; however, whether and how ENDS could contribute to public health goals remains uncertain. Disagreements continue over their long-term risks, 2 the effect of second-hand ENDS aerosol, 3 and whether ENDS support or inhibit smoking cessation. [4][5][6] Systematic reviews published in 2021 indicated ENDS may be marginally more effective for smoking cessation than nicotine-replacement therapy, yet the data included in those reviews do not suggest they are a panacea that will end the smoking pandemic. 7,8 For instance, one concluded that for every 100 people using nicotine-containing ENDS to stop smoking, approximately 9-14 people would stop successfully, compared with approximately 6 of 100 people using nicotinereplacement therapy. 8 Furthermore, significant concerns persist over ENDS' appeal to youth 9, 10 and potential "gateway" role to tobacco smoking. 11 Patterns of youth and young adult ENDS use vary across countries. For instance, in the United States, around 20% of high-school students and 5% of middle-school students were current ENDS users in 2020, 12 and the prevalence of ENDS use among those groups appears to be declining. In contrast, in many other countries including Australia and New Zealand, youth and young adult ENDS use is increasing and is highest among those aged 18-24 years old; in 2019, 5% of Australian 18-24 year olds were current ENDS users (defined as at least monthly usage), 13 compared to 21% in New Zealand. 14 Differences in ENDS use across countries reflects policy variations in how ENDS are regulated, 15,16 and debate continues across scientific, advocacy and policy communities about the best regulatory approach. 17 This regulatory divergence creates incentives for stakeholders and interest groups to influence policy using the media, including social media, to present an issue, communicate arguments and potential solutions, and mobilize support. 18 Despite ongoing debates about ENDS' potential risks and benefits, and impact on smoking cessation, several studies report that the "Twittersphere" of ENDS-related information is dominated by endorsements of ENDS as effective smoking cessation aids. [19][20][21][22][23][24] For example, a 2015 study of ENDS-related Twitter conversations concluded that pro-ENDS narratives shaped discussions about ENDS bans or taxation. 25 Tweets questioned scientific evidence of ENDS' health risks, argued ENDS regulations would have unintended consequences, and presented ENDS as life-saving smoking cessation devices. 25 Some research identified coordinated efforts by ENDS proponents, including "Twitter bombing" to oppose regulation, 26 and counter-campaigns that parodied public health initiatives. 27,28 On March 22, 2012, ENDS advocacy organizations, including Consumer Advocates for Smoke-Free Alternatives Association (CASAA), initiated the first "World Vaping Day" (as it was originally called before being renamed "World Vape Day"). 29 While many national and regional ENDS advocacy campaigns exist, WVD has become a significant global advocacy platform for ENDS proponents, who have used it to try to influence the World Health Organization (WHO). For instance, CASAA's 2014 WVD "International Call to Action" urged ENDS consumers to contact the WHO to oppose bans on ENDS use in public places and present evidence suggesting exposure to second-hand ENDS emissions is not harmful. 30 The recent rescheduling of WVD, which moved to 30 May in 2020, one day prior to the WHO's World No Tobacco Day, arguably attempted to integrate pro-ENDS messages into the WHO's anti-tobacco campaign. The International Network of Nicotine Consumer Organisations (INNCO), an umbrella organization for national and regional ENDS consumer advocacy groups that has received funding from the Philip Morris International-funded Foundation for a Smoke-Free World (FSFW), 31, 32 managed the 2020 WVD website. The World Vapers' Alliance, another key organization involved in WVD, is also reportedly supported by tobacco industry funding. 33,34 The campaign used specially created WVD-branded images and messages, and disseminated these via Twitter (@ worldvapeday) as well as Facebook and Instagram (see: www. facebook.com/WorldVapeDay and https://instagram.com/ world_vape_day). The WVD website encouraged ENDS users to participate by posting testimonials and stated that: "Our goal is to present an assortment of compelling individual reports that will make it impossible for anyone to claim that substitution of low-risk alternatives is not a proven method for quitting smoking". 35 Evidence WVD has become a more organized global advocacy campaign highlights the need to examine how its messages are used to influence policy, given arguments made in these are likely to be repeated across many jurisdictions, regardless of differences in policy context. We focused on Twitter data, since Twitter has provided a popular platform among policy advocates, and earlier analyses of Twitter data have provided valuable insights into policy debates. 31,36,37 We analyzed tweets posted as part of WVD 2020 to identify and critically review the arguments presented.

Data Collection
Using automated scraping, we downloaded a dataset of tweets that included the hashtag #WorldVapeDay. We collected 58 551 tweets posted over eight days from May 26 to June 3, 2020 (World Vape Day was on May 30, 2020). After excluding non-English language tweets, the dataset comprised 39 471 tweets (4387 original tweets and 35 084 retweets) from 2289 unique users. We assigned each original tweet an identifier and used an online random number generator (www.numbergenerator.org) to draw a random sample of just over half of the original English language tweets (n = 2200) for content coding. We used NVivo12 to manage the content coding.

Coding and Analysis
LR and JH reviewed the Twitter data and developed a draft codebook to classify tweets that put forward an argument, position, or call to action in relation to ENDS. Our primary analysis used qualitative thematic analysis and emergent (rather than a priori) coding to develop codes from the tweets 38, 39 ; we coded concurrently and iteratively for a supplementary content analysis, where we compared the relative frequency of the different arguments. LR and JH tested the initial codebook with a random sample of n = 200 tweets; EL coded the same n = 200 tweets as a training exercise before LR reviewed the coding and refined the categories and coding processes. LR and EL next independently coded a second random subset of n = 200 tweets and assessed inter-rater reliability using Cohen's Kappa. Arguments with a minimum of 20 coded tweets (n = 17) were assessed (as the effect of bias is greater with a smaller number of comparisons), 40 with a resulting average Kappa = 0.68. LR and EL discussed and resolved coding discrepancies (re-coding where necessary and as mutually agreed) and further refined definitions and delineations. A third random subset of n = 200 tweets was coded using the same process; Cohen's Kappa increased to 0.77 and the percentage agreement averaged 96.3%. EL randomized and coded the remaining tweets. LR, EL, EF, and JH met regularly to review the coding, and discuss, compare and agree on classifications. After coding all arguments and positions, LR, EL, EF, and JH met and developed the four over-arching themes these supported: Harm reduction, smoking cessation, rights and justice, and opposition to ENDS restrictions. Supplementary File 1 contains the final codebook and illustrative tweets.
Tweets that did not advance an argument, position, or call to action in relation to ENDS, or that contained insufficient or incomprehensible text, were coded as "no argument" and excluded. We did not include tweet hashtags in our qualitative analysis unless they were integrated into the core message of a tweet and thus helped communicate the argument, position or call to action. However, we undertook a supplementary descriptive analysis to identify the most common hashtags. Supplementary File 2 provides an overview of the analytical process. Table 1 shows the most prevalent arguments relating to each of the four themes we identified. Arguments with fewer than 10 coded tweets are shown in Supplementary File 3. Because tweets including only a "call to action" differed qualitatively from those containing an argument or position, we present the number of coded "call to action" tweets in Supplementary File 3. Any tweets containing both a "call to action" and an argument are included in Table 1.

Thematic Analysis Harm Reduction
Tweets in the harm reduction theme presented ENDS as a less harmful, safer, or "healthier" alternative to smoking. Some comments compared ENDS to other risk reduction strategies: "Motorcycle helmets, condoms, masks, shoes, clothing, hard hats, sunscreen, seatbelts, sunglasses, ear plugs. We all practice [sic] harm reduction literally every day . . .". Several cited scientific references: (eg, "British Medical Association: There are clear potential benefits to #ecig use in reducing the substantial harms associated with smoking, and a growing consensus that they are significantly less harmful than tobacco use"). Others referred to Public Health England's conclusion that ENDS are 95% less harmful than smoking (eg, "We already know #vaping is at least 95% safer than smoking!"). Tweets substantiated harm reduction arguments using claims about improved health outcomes (eg, "Switch to vaping and improve your heart and lung health").
Several tweets argued that nicotine is not harmful and implied ENDS avoided the serious risks caused by cigarette constituents (eg, ". . . people smoke for the #nicotine but die from the TAR.", and "how many people die from #nicotinevaping? It's an easy one, zero"). Tweeters argued that vaping is not smoking by claiming that ENDS do not combust or produce smoke, hence could not be smoking: ". . . Something must at least contain smoke to be rightfully called smoking. Where there's no smoke, there's no one smoking." Seventeen tweets asserted that second-hand ENDS aerosol was not harmful and framed emissions as having either "minimal" or no toxic effects (eg, "..there are no proven health risks of second hand vaping to the health of bystanders. Vaping could prevent millions of deaths from secondhand smoke"). Six tweets (see Supplementary File 3) diminished ENDS' potential risks by comparing these to daily life activities: ". . . Relative risk matters, and relative to smoking, drinking, and other risky behaviors people engage in, vaping nicotine is pretty benign".

Smoking Cessation
Most tweets in this theme used personal testimonials to present ENDS as an effective smoking cessation aid. Comments typically outlined how long individuals had smoked, when they had switched to using ENDS, the e-liquid flavor used, and the ease of quitting by using ENDS (eg, "I'm a survivor. I stopped smoking with pistachio cream and peanut-waffle flavored e-liquids. Nonsmoker since 2018. Started smoking when I was 12 years old, smoked for 47 years"). Testimonials frequently claimed that ENDS save lives, support quitting, and are superior to other smoking cessation methods, such as nicotine replacement therapy (NRT): "I'm 60 years old and smoked for over 37 years. Tried every Pharma and NRT product to quit --they all failed. If it wasn't for E-liquid Vape Products getting me off cigarettes, I would still be smoking (or I would be dead from smoking)". Many corroborated these arguments by outlining improvements in symptoms experienced when smoking: ". . . almost 5 years smoke free, and feeling and breathing a lot better than before", or by citing cessation rates to highlight ENDS' superiority over other cessation approaches: ". . . [vaping] has an amazing 18% cessation success rate".
Personal stories also outlined the effects of smoking on loved ones and ENDS' potential life-saving effects for individuals (eg, "I wish vaping would've been around to save my dad. My dad died when I was 14 of emphysema due to horrible combustible cigarettes") and the population (eg, "Cigarettes kill 480,000 Americans a year!"). While nearly all tweets in this theme hailed ENDS as an effective cessation aid, few referred to dual use (ie, concurrent smoking and ENDS use), which may impede smoking cessation (see Supplementary File 3).

Rights and Justice
Tweets in this theme asserted users' freedom to choose ENDS, and framed access to ENDS as a human right and civil liberty (eg, "It's your right to choose a less harmful product!"). Tweets encouraged others to "fight for their rights": "Everyone has the right to quit smoking combustible cigarettes. Everyone should have the right to use vaping to do that. I will always fight for people to be able to quit smoking like I did". Numerous tweets represented nicotine users who did not or could not quit smoking as having been abandoned without cessation options (". . . people don't deserve to die just because they use nicotine"). Tweeters implied authorities misled the public about ENDS and claimed people had the right to know the truth that ENDS were effective cessation aids (eg, "The American people have a right to know the truth about flavored nicotine e-liquid vaping; 0 deaths 18% cessation, 80% smoker transition, 95% less harmful.") Rights-based arguments frequently claimed that ENDS flavors supported smoking cessation (eg, "Quitting smoking was made possible for me and millions of others by way of flavored vapes") and highlighted the importance of flavors to adult former smokers: "I am 34 years old and flavored vapor products helped me quit a 15 year habit. Adults like flavors!". Presenting ENDS as an adult product implicitly rejected flavors' appeal to young people and privileged the potential benefits adult smokers could gain from switching to ENDS above the potential risks nonsmoking youth would face from ENDS uptake: "Politicians are using the kids as a shield but turn a blind eye and deaf ear to adults that have quit deadly combustible cigarettes. It's time to listen and see that vaping isn't trying to hook kids. It's about savings adults' lives" and "I am an adult. I have the right to make a less harmful choice. Please do not take away this right from me. Bring strong laws to control youth vaping, but don't punish.. Indian smokers." Several tweets claimed that youth trial of ENDS was inevitable, though minimized the population health risk

Harm reduction
Makes a general harm reduction claim(s) without specific 95% claim; frames ENDS as low-risk, lower risk, or a safer alternative.

22%
At least 95% less harmful Includes a reference to the "ENDS are 95% safer than smoking" claim (or cites a higher %, such as "99% safer").

8%
Nicotine not harmful States that nicotine itself is not the harmful constituent of cigarettes. 76 5% Improved health outcomes Claims switching to ENDS from smoking leads to improved health outcomes (i.e., generally rather than personal experience).

4%
Vaping is not smoking Makes argument or statement about how vaping is not smoking. 34 2%

secondhand vape not harmful
States that secondhand aerosol produced by ENDS is benign or harmless. 17 1%

Testimonial
Promotes ENDS use using a testimonial from a former cigarette smoker. 272 17%

Improved symptoms
Refers to tweeter's own improved health/ symptoms, which they attribute to ENDS (i.e. subset of testimonials).

2%
ENDS save lives Describes ENDS as life-saving or as having saved the tweeter's own life 239 15%

ENDS support quitting
Refers to or frames ENDS as a smoking cessation or "quitting" aid (excludes testimonials).

5%
Effects of smoking Refers to smoking-related harm either at population level or effects on loved ones.

4%
ENDS' superiority States ENDS are more effective/ better than other cessation methods. 56 4%

Access to flavors
Refers favorably to flavored ENDS (i.e. importance of flavored ENDS in stopping smoking).

11%
Right/ freedom to choose Argues smokers' access to ENDS and/ or harm reduction is a human right; smokers/ adults) should have freedom of choice.

10%
Vaping is for adult smokers Frames ENDS as targeted at and/ or used by adults and/or smokers only; not for children or youth.

Industry is consumerdriven
Frames ENDS as developed and made by smokers for smokers; ENDS industry as consumer-driven/ grassroots.

Involve consumers
Argues policy-makers/ regulators must listen to, learn from and/ or involve ENDS consumers in ENDS policy-making.

2%
Don't deserve to die Argues nicotine users "do not deserve to die". 21 1%

Refutes "gateway" hypothesis
Refutes the idea or evidence that vaping can lead to smoking.

1%
Right to know the truth Argues public have the "right to know the truth" about ENDS, or have a right to be fully informed.

Youth ENDS trial inevitable
Argues cannot prevent all youth from ENDS experimentation and/ or refutes concern over youth ENDS trial or usage.

Criticism of those perceived as opposing ENDS
Criticizes individuals or organisations perceived as opposing ENDS; tweet may include "Quit or Die" mantra in reference to tobacco control efforts.

Misinformation about ENDS
Argues or implies "misinformation" and/ or selective evidence used about ENDS; calls for "evidence"; implies ENDS advocates disseminate factual information.

Repeal ENDS ban
Appeals for an existing ban on ENDS to be removed e.g. in India or Australia. 69 4%

Restrictions unjustified
Frames restrictions on ENDS as prohibition; argues restrictions are unnecessary, unjustifiable, infeasible or ineffective.

4%
Unintended consequences Refers to possible unintended consequences of policies such as flavor bans, or a ban on ENDS.

2%
International comparisons Refers to countries with desirable ENDS policies e.g. NZ or UK, or to those with undesirable policies e.g. Australia or India.

1%
N.B. *Total coded tweets (n = 1590; ie excluded n = 610 tweets containing no argument). ^Proportion indicates the % of n = 1590 tweets that included the argument; tweets were not mutually exclusive. Our definition of "argument" is expanded to include types of evidence (ie, Testimonials). Coding of arguments with fewer than 10 tweets is shown in Supplementary File 3, as is coding of "Call to Action" tweets (any specific arguments conveyed in the latter group of tweets are included in the table above).
involved or refuted the gateway hypothesis (e.g., "Youth are experimenting with vaping but experimentation alone is not a serious public health problem. Importantly, regular vaping among young people is rare and confined almost entirely to those who already smoke"). Tweeters thus argued that youth ENDS use did not justify restrictions they thought would impinge on adults' rights (eg, "Taking rights away from adults doesn't protect kids") and held parents and adolescents themselves, not the ENDS industry, responsible for youth vaping. This reasoning enabled them to reject ENDS restrictions: ("Parents, parent your kids and leave adult choices available for smokers!" and "I am an adult and I love flavored vapor products. Law abiding adults shouldn't be punished for adolescent criminals").
Tweets also appealed to regulators to involve consumers in policy-making and recognize them as principal stakeholders. While some tweets adopted a defiant tone ("We are #vapersvoice and we will not be #silent"), others presented ENDS users as experts who embodied ENDS' effectiveness as a smoking cessation aid ("Data is evidence. The evidence is real. Check out more of the thousands [of] success stories submitted by REAL people . . ."). Framing ENDS as a consumer-driven, grassroots industry authenticated these arguments and sharply differentiated ENDS users from tobacco companies: "Vaping is a miraculous phenomenon on smoking cessation and public health exclusively led by consumers: we are not Big Tobacco!".

Opposition to ENDS Restrictions
Tweets in this theme challenged groups seen as unsupportive of ENDS and disparaged restrictive ENDS regulation. The most prevalent tweets criticized individuals or organizations perceived as opposing ENDS; for example, some tweets accused public health groups of having a vested interest in sustaining smoking to avoid jeopardizing tobacco control funding (eg, "The ones that say no to THR are the ones profiting and collecting blood money from smokers. They lie about vaping so that you will hate the idea too"). Many tweets accused the WHO of immorality (eg, "We do know that the @WHO is for sale and has been bought out by the tobacco economy and now markets to children, however. Happy #WorldVapeDay you lying bastards"). Tweets contrasted public health groups' alleged spread of misinformation (eg, "They are using media to create panic a 'youth epidemic' and spread misinformation to continue to profit from the established tobacco/pharma revenue stream!") with ENDS advocates' dissemination of factual information: "thank you to the #vaping community for so much passion, fortitude & most of all FACTS that were shared this weekend".
Many tweets presented ENDS restrictions as unjustified and argued that nicotine abstinence is not realistic: "Bans don't work, vape bans especially not, since nicotine is freely available in many other forms. Why ban the least harmful of them?". These claims supported calls to repeal restrictions (eg, "Vaping, it saved my life, it's the best NRT. We have to #EndVapeBan in India") and warnings of adverse unintended consequences: "Bans/taxes just force adults/youth back to smoking that kills 1,300/day". Tweets used international comparisons to illustrate risks and benefits of different regulatory approaches: "Several countries which banned e-cigarettes including Mexico, Brazil and Thailand saw a booming black-market -making it difficult for government to regulate the sales of these products") and "The UK is a great example of a country encouraging smokers to switch. The switching rate is much higher than in other countries because they have embraced it". While many tweets criticized individuals or organizations perceived as opposing ENDS (n = 448), very few (n = 9) criticized the nicotine or tobacco industries (see Supplementary File 3). Table 2 shows the ten most frequent hashtags, other than #WorldVapeDay. The most common, #SayYesToTHR, resembles an overt political message aimed at policy-makers, and several other frequently used hashtags reference either the WHO, World No Tobacco Day (WNTD), or the official WNTD2020 hashtag: #TobaccoExposed (indicated in bold text in Table 2). In contrast, hashtags containing more descriptive language, such as #harm reduction, #THR and #tobaccoharmreduction were far less prevalent (2%, 2% and 1%, respectively; not shown in Table 2).

Discussion
We identified four main themes in the tweets tagging the 2020 World Vape Day Twitter campaign: harm reduction, smoking cessation, rights and justice, and opposition to ENDS restrictions; those themes, and the specific arguments we identified, reflected campaign memes and messages disseminated by WVD organizers (eg, http://www.facebook. com/WorldVapeDay and https://instagram.com/world_vape_ day). The most prevalent messages criticized those perceived as opposing liberal ENDS regulation, such as the WHO and other public health agencies, and represented them as immorally spreading disinformation about ENDS to maintain (rather than reduce) smoking prevalence. Widespread use of hashtags associated with the WHO enabled WVD tweets to "piggyback" on the trending topic of World No Tobacco Day and increase WVD messages' reach. 20 In contrast to previous studies, 19,42 we found very few overtly commercial ENDS messages (ie, those advertising specific ENDS products), which may reflect the evolution of WVD into a political campaign (rather than a more general absence of commercial ENDS tweets on Twitter). Instead, WVD messages promoted ENDS and "harm reduction" more generally, and the campaign appeared largely directed at regulators. WVD organizers encouraged personal testimonials that presented ENDS as a life-saving smoking cessation aid, in the hope of changing the attitudes of "those who want to restrict access to e-cigarettes and other smoke-free products". 35 ENDS consumer groups with industry links were involved in organizing WVD, including CASAA (founded and governed by ENDS industry representatives as well as consumers, 29,43 ) and INNCO (a Foundation for a Smoke-Free World grantee and thus an indirect recipient of PMI funding). 32 Another organization central to WVD 2020, the World Vapers' Alliance, which hosted a global online YouTube event as part of the campaign, 44 has subsequently been the subject of investigations into its funding sources. 45 One investigation claimed British American Tobacco has played "a central and hands-on role in orchestrating, directing and funding" the World Vapers' Alliance and its social media activities. 34 The links between key organizations involved in World Vape Day and the ENDS industry have important implications. The tobacco industry's long history of creating and using third parties (including consumer groups) to disseminate its arguments, 46 along with allegations of BAT's involvement in the World Vapers' Alliance, 34 gives rise to the possibility that industry actors shaped the pro-ENDS messages disseminated during WVD. Direct industry involvement would raise questions about the ostensible grassroots nature of the WVD campaign and thus the validity of some of the arguments advanced. While it is beyond our study to conduct a full critical analysis of the WVD arguments, other research has outlined limitations in the industry's "harm reduction" arguments, 47,48 and criticized ENDS proponents' use of rights-based arguments that privilege adult smokers' rights over children's. 49 Furthermore, although messages endorsing ENDS as effective smoking cessation aids dominate the "Twittersphere" of ENDS-related information, [19][20][21][22][23][24][25] ENDS' effectiveness as smoking cessation tools remains disputed, given a lack of rigorous randomized controlled trials. 7 Lastly, although WVD appeared to target ENDS policy actors, 35 the promotion of personal testimonials could represent a form of viral marketing promoting ENDS to nonusers. While Twitter has a policy banning tobacco advertising that applies to "alternatives which imitate the act of smoking" and "events sponsored by tobacco manufacturers", 50 it is unclear how that policy affects campaigns such as WVD, where industry links are neither declared nor apparent.
How could public health advocates address pro-ENDS campaigns such as WVD? Advocates could become more proactive in social media debates around ENDS; doing so could foster a clearer balance between ENDS proponents and health perspectives, 19,51 given health professionals typically do not engage in social media discussions. 24,52 While research suggests public health social media campaigns can change individuals' attitudes, few studies have examined whether public health advocates' real-time responses that aim to balance policy discussions are effective. Further research could examine how health advocates might engage in policy campaigns to support balanced messaging and informed policy-making. While social media platforms are increasingly used to influence policy actors, 53 using Twitter to promote pro-ENDS messages is likely part of a wider strategy to influence ENDS policy, and the arguments we identified will likely appear in other outputs and lobbying activities. Our findings can thus inform possible responses by advocates, such as counter arguments where appropriate, using more varied platforms than Twitter alone. Further research could examine the extent to which WVD arguments have been adopted in policy-making proposals and wider stakeholders' submissions on potential policy. Ongoing analysis of relationships between pro-ENDS campaigns and ostensibly independent entities that promote liberal regulation would help identify potential conflicts of interest that may not be immediately apparent, and would support compliance with FCTC Article 5.3. 54 Lastly, public health advocates could continue advocating for greater regulation of social media to reduce all forms of nicotine and tobacco product promotions. 55 Our study has several limitations. Our dataset may not have captured every tweet containing #WorldVapeDay and we did not include tweets from private Twitter accounts as we used Twitter's public API. We analyzed a random sample of half, rather than all, the original tweets in our dataset, though random selection of the analyzed tweets means these are unlikely to differ systematically from those we did not analyze. The frequency table (Table 1) presents the most frequent themes and arguments, rather than outlining a precise estimate of the tweets conveying a particular argument. However, our use of manual coding, and the intensive consultation and review process used during the analysis, are important strengths that enabled the detailed qualitative examination required by our research question, and identified the prominence of rights-based arguments.
Policy-makers need to consider diverse arguments for and against liberalizing ENDS. Analyzing Twitter activity associated with WVD and the core arguments advanced has identified potential conflicts of interest, including roles played by industry-linked groups such as CASAA, INNCO and the World Vapers' Alliance. By highlighting efforts to embed pro-ENDS messages into the WHO's WNTD campaign, our analyses support a more informed and dispassionate assessment of ENDS advocates' most common arguments. Tobacco control researchers and advocates should continue to monitor and report on obfuscated relationships between the nicotine industry and ENDS advocacy groups.

Supplementary Material
A Contributorship Form detailing each author's specific involvement with this content, as well as any supplementary data, are available online at https://academic.oup.com/ntr.

Funding
EL was supported by the Health Research Council of NZ (programme grant 19/641). LR, AJ, KER acknowledge the support of Bloomberg Philanthropies' Stopping Tobacco Organizations and Products project funding (www. bloomberg.org). LR also acknowledges funding from a Royal Society Marsden Fast-Start grant UOO2028. The opinions expressed are those of the authors alone. The funders had no role in study design, data collection, analysis, decision to publish, or preparation of the manuscript.

Declaration of Interests
The authors have no competing interests to declare.

Contributorship
LR and JH conceptualized the research and all authors contributed to the final study design. AJ and KER collected the data. AJ conducted preliminary descriptive data analysis. LR and JH developed the initial codebook, with input from EF and KER. EL and LR conducted the data analysis, and JH and EF supported the refinement of themes and arguments, and data interpretation. EL prepared a draft manuscript; LR and JH substantially revised this version, on which EF provided feedback. AJ and KER critically reviewed an advanced version of the manuscript. All authors approved the final submitted version.

Data Availability Statement
The data underlying this article will be shared on reasonable request to the corresponding author.